Automatic safety door lock for motor vehicles



Get. 8, 1940. c. H. PRESTON AUTOMATIC SAFETY DOOR LOCKFOR MOTOR VEHICLES 2 Sheets-Sheet 1 Filed NOV. 3, 1938 INVENTOR Charles H. Presion.

ATTO R N EY Oct. 8, 1940. c H PRESTON Y 2,217,495

AUTOMATIC SAFETY DOOR LUCK FOR MOTOR VEHICLES Filed Nov. 3, 1938 2 Sheets-Sheet -2 INVENTOR v Charles Hfireszon ATTORNEY Patented Oct. 8, 1940 UNITED STATES PATENT OFFICE AUTOMATIC SAFETY DOOR LOOK FOR MO- TOR VEHICLES '1 Claim.

This invention relates to new and useful improvements in an automatic safety door lock for motor vehicles.

The invention has for an object the construc- 5 tion of a lock as mentioned which is controlled by a mechanism associated with the speedometer drive.

The invention contemplates .the provision of a mechanism characterized by a rotative spindle 10 connected with the speedometer drive shaft, either directly or indirectly, for controlling a circuit in a specific manner for controlling the door locks of a vehicle.

More specifically, the invention contemplates l6 connecting the rotative spindle with the flexible drive shaft of the speedometer at a point where the flexible casing of the speedometer is split so that the connection with the rotativespindle may be accomplished with greater ease.

m Still further the invention proposes an emergency arrangement for releasing the door locks in the event of emergency.

For further comprehension of the invention, and of the objects and advantages thereof, ref- 35 erence will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure I Fig. 1 is a side elevational view of a motor vehicle provided with a conventional speedometer and with an automatic safety vehicle door lock according to this invention.

Fig. 2 is a fragmentary sectional view of a portion of Fig. I particularly disclosing the device, and to which schematic wiring has been added to fully disclose the construction.

Fig. 3 is a fragmentary elevational view looking 0 in the direction of the line 3-3 of Fig. 2.

Fig. 4 is a horizontalsectional view on the line ll of Fig. 3.

Fig. 5 is a fragmentary side elevational view m the line 8-8 of Fig. 7.

Fig. 9 is a fragmentary vertical sectional view of a modified form of the device, this view being taken on the line 9-9 of Fig. 10.

Fig. 10 is a vertical sectional view taken on u the mm 10-40 r Fig. 9.

Fig. 11 is a fragmentary vertical sectional view similar to Fig. 9 but illustrating a further modified form.

Fig. 12 is an end elevational view of Fig. 11.

The automatic safety door lock device for ve- 6 hicles is intended to be used in combination with a motor vehicle l0 having a conventional] speedometer II which is connected by the conventional flexible drive shaft l2 housed within a flexible cable 13, with one of the wheels, as illus- 10 trated, the front wheel I 4 of the motor vehicle. The device includes a spindle l5 provided with a pinion I8 and rotatively supported in a hearing I! which is mounted in a support block I8.

A fastening element I9 is adapted to station- 15 arily secure the support block I8 upon a portion 10 of the motor vehicle. The pinion l6 meshes with a gear fixed upon a shaft 2| rotatively supported in a bearing 22 mounted within the support block I8. The gear 20 meshes with a gear 20 23 fixed upon the speedometer drive shaft 12. The flexible tubular cover l3 of the drive shaft 12 is supported by brackets 24 mounted upon a portion IU" of the motor vehicle.

A pair of opposed semi-cylindrical contacts 25 2r and 26 are stationarily mounted in slightly spaced positions coaxially about the spindle l5 upon the support block I8. Fastening elements 21 serve to secure the shells upon the block. The shells 25 and 26 are connected with a circuit as here- 30 inafter more fully described. This circuit includes leads 30 and 3|.

A hub 32 is mounted upon thespindle I5 and is disposed within the shells 25 and 26. Several radial arms 33 radially project from the hub 32 35 and, terminate a short distance from the skirt Walls of the shells 25 and 26. A leaf spring 34 is fixedly mounted at one of its ends upon one of the radial arms and at its free end supports a small weight 35. The arrangement is such that 0 when the hub 32 rotates centrifugal force will flex the leaf spring 34 and cause it to contact the inner face of the skirt wall of the shells.

An arcuate member 36 is mounted on another one of the radialarms 33 at one of its ends by a pint1e31. 'At its other end the arcuate member 36 is formed'with a fork portion, the fingers of which engage opposite faces of another one of the radial arms 33. This latter radial arm is provided with a pin 38 which limits inward pivoting of the arcuate member. A tension spring 39 is connected between the arcuate member 36 and the hub 32 and normally holds the arcuate member against the pin 38.

The arrangement is such that during rotation spindle l5 which then rotates the hub 32.

of the hub, centrifugal force will cause the free end of the arcuate member 36 to move outwards against the action of the spring 36 so that it contacts the shells 25 and 26.

The leads 30 and 3| are connected in a circuit which includes in series a source of power 46, a signal lamp 4| and the coil 42 of a relay. This relay is provided with a relay switch 43 urged into an open position by a spring 44. Energizetion of the relay causes the switch 43 to move against a contact 45 and close an auxiliary circuit. This auxiliary circuit includes in series a source of power 46 and the casing 41 of a door lock for the vehicle. This casing 41 is grounded at 48. The door lock is of conventional design and has a handle 49 by which it may be opened and closed. The bolt 50 of the door lock engages within a keeper in the frame 5| of the door. A latch device is provided for latching the bolt 50 in its closed position. This latch includes a solenoid 52 having a core 53. The coil of the solenoid 52 has one of its ends grounded at the point 54. Its other end connects with the contact 45.

A spring 55 is engaged upon. the core 53 of the.

solenoid to normally urge the core upwards into an open position. An emergency cable 56 connects with the solenoid core 53 and extends through a passage 51 to the operator of the motor vehicle to passengers within the vehicle. A handle 58 is connected with the outer end of the cable 56 by which it may be conveniently drawn to release the latch 53.

The operation of the device is as follows:

When the vehicle is standing still the speedometer shaft I2 is not rotating. Consequently, the contact spring 34 and the arcuate member 36 are out of contact with the shells 25 and 26. The primary circuit is therefore open and no current flows. The lamp 4| is not lit. The spring 55 holds the solenoid core 53 in a raised position out of the bolt 50 of the lock. The door lock may therefore be opened. Thus when the vehicle is stationary all of the'doors are free to be opened.

As soon as the vehicle moves the speedometer shaft turns. This rotation is transmitted to the stantly the leaf spring 34 makes contact due to centrifugal force, with the shells 25 or 26 depending merely in which position the hub happens to be at the particular instant. Similarly, the arcuate member 36 is also making contact with one or the-other of the shells or simultaneously with both of the shells. The primary circuit is therefore closed since current may now flow from the lead 30 to the lead 3|. The lamp 4| is then illuminated. The relay operates to close the secondary circuit.

The secondary circuit energizes the solenoid 52 and its core 53 moves downwards engaging the bolt 50. Now the door lock is latched closed and cannot be opened. It should be understood that the automatic safety door lock may be ap plied to all of the doors of the motor vehicle, or it .may be applied to each of the doors excepting the key lock door. In the event of emergency, should it be required to open the doors, though the vehicle is moving, it is merely necessary that the emergency handle 56 be pulled. This will cause the solenoidcore 63 to be moved free' from the bolt 50. The door is now free to open.

In Figs. 5 and 6 a modified form of the invention has been disclosed which distinguishes from the prior form merely in the fact that the spindle |5 which supports the hub 32 is directly connected with the speedometer shaft II. The

speedometer shaft extends through the flexible casing l3. At the coupling, one end of the flexible casing I3 is supported by a bracket 24'. The other end is supported upon the support block l6. Turning of the speedometer drive shaft l2 will directly rotate the hub 32. In other respects this form of the invention is similar to the previous form.

In Figs. '7 and 8 a still further modified form of the invention has'been disclosed which distinguishes from the prior forms in the fact that an arrangement has been provided whereby it is possible to control the instant of operation of the safety device. For example, it is possible to cause the safety device to operate only when the vehicle is moving at a speed greater than three miles an hour, or at some other small speed.

The adjustment is characterized by providing a spring 66 connected at one end of the leaf spring 34 and at its other end to a bracket 6| which is adjustably mounted on one of the radial arms 33. A clamp screw 62 engaging through a slot in the bracket threadedly engages the radial arm 33 and serves to adjustably hold the bracket as required. The spring 36 is connected at its outer end with the arcuate member 36. At its inner end it is connected with an auxiliary hub 32'. This auxiliary-hub is adjustably mounted on the spindle |5. There is a set screw 63 engaging through the auxiliary hub 32, and abutting the spindle |5" for holding the auxiliary hub in selected positions. It is possible to shift the auxiliary hub to vary the tension of the spring 36.

It will be noted that it is possible to control the tension of the springs 39 and 66 for delaying or advancing the contacting of the leaf spring 34 and the arcuate member 36 with the shells 25 and 26 according to predetermined speeds of rotation of the spindle.

In Figs. 9 and 10 a still further modified form of the invention has been disclosed which distinguishes from the prior form in the manner in which the circuit is controlled through the device. According to this form of the invention there is a single cylindrical shell 25 which is formed with a relatively large central opening 63 avoiding the spindle IS. The spindle 5 is rotatively supported and connected with the flexible, drive shaft of the speedometer as explained in Figs. 1 to 4. The spindle I5 is provided with a projecting rear portion I5 upon which there is a contact wheel 65. This contact wheel is engaged by a brush 66 connected with the cable 3|.

The cable 36 is connected with the shell 26. A hub 32 is mounted upon the spindle |5 within the shell 25' and is formed with an opening through its center. Within this opening there is a shaft 61. This shaft is provided with a cylindrical portion 66 slidably supported by several rollers 66. A spring 16 acts to urge the shaft inwards. The shaft is provided with a weight II at its extended end. The arrangement is such that when the hub 32 rotates centrifugal force will urge the shaft 61 outwards so that its outer end contacts the shell 25'. A circuit will then be closed from the lead 36 to the shell 25', to the radial arm 61, the hub 32', the spindle I6, the extension IS", the wheel 65, the brush 66 and the lead 3|.

In Figs. 11 and 12 another modified form of the invention has been disclosed which distinguishes from the prior forms specifically in the construction of the centrifugal elements. According to this form of. the invention the spindle iii's provided with a disc hub 82'; Several segmental weights 13 are radiallyslidahlymountedi on thedisc 32?. Each 0!. the segments II isprovided with a radial slot N. Several plus I! projectfrom the disc 32* andiengage slots; Thus the segments are radially slidably supported, A spring 16 is mounted in each one o! the slots 14' and acts between one of the ends; of the: slot and one of the pins for resiliently urging the ferred embodiments of my invention, it is to be understood that I do not limit mvseli'i to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope or the invention as defined in the appended claim.

Having thus described my invention, what I claim as securehyUnlted States Patent-k:

In adeviiaeoftheclnss described. a rotative spindle, contacts stati'onarily mounted coaxially otsaidspindleshnh smndle, a armvtrom said hub, anarcuate member pivotally' mounted on said arm and adapted to move outwards and contacts duetocentrifugal lorce when said spindle turns, resilientmeans Ior holding said arcuate member-inwards until a speed at,

turn isreached; andmeanstorvarying the ten-v sion oisaidresilientmeanstochangethepredetermined speed at which said arcuate munher will. move outwardsto engage said contacts. said resilient means comprising a coil spring. said latter-mentioned. means comprising an auxilary hub rotatively mounted on said spindle, said spring having one end mounted on said arcuate member and its other end attached to said hub, and means tor holding said hub in various rotative positions on said spindle to increase or decrease the tension of mid spring comprising a set screw threadedly engaged through said auxiliary hub and spindle.

CHARLES H. PRESTON. 

